Embodiments of the present specification relate generally to spectroscopic measurements, and more particularly to systems and methods for determining a parameter profile in multiple dimensions corresponding to a parameter in an exhaust emission.
Industrial plants and combustion based machinery emit gaseous effluents from the exhaust during operation. Emission of gaseous effluents are constrained by regulatory limits. Analysis of gaseous effluents from the exhaust chamber aids in estimating a plurality of emission parameters such as, but not limited to, a temperature and a pressure of the exhaust emission or a concentration of a species in the exhaust emission. Emission parameters may be used for controlling the operation of the industrial plants to comply with the regulatory requirements. Further, the emission parameters may also be used to determine the health of an engine such as a gas turbine used in the industrial plants.
Conventional in-situ, non-contact techniques entail passing a laser beam through the exhaust emission to measure the emission parameters. In traditional line-of-sight techniques for measuring the emission parameters, an average of parameter values along a laser path is acquired. However, in many applications, heat transfer with the side wall of a combustion chamber, cold boundary layers, gas diffusion, and other effects result in non-uniform temperature and pressure distributions along the laser path, thereby adversely affecting the measurement of the emission parameters.
Additionally, measuring/determining intermediate values of the emission parameters at multiple locations along the laser path may not be practically feasible. Moreover, measuring emission parameters in a two-dimensional (2D) space or a three-dimensional (3D) space poses additional challenges. For example, measuring the emission parameters at multiple locations along a line, a 2D surface, or in a 3D volume is a time consuming and laborious task. In some scenarios, positioning the measuring device at one or more of these multiple locations may be an onerous task. Further, currently available measurement setups may not be suitable for performing measurements of all parameters related to the exhaust emission and species in the exhaust emission. In addition, the instrument setup may be bulky and non-portable.